The invention is based on a sabre saw.
From Published, Non-Examined German Patent Application DE-OS 41 02 011, a sabre saw is already known whose reciprocating rod, on its lower end, receives the chucking end of a saw blade with two opposed lugs extending crosswise to the longitudinal axis of the saw blade. The chucking end of the saw blade is introduced axially into the reciprocating rod until the lugs on their ends meet the lower end of the reciprocating rod.
A centering slot for receiving the saw blades is disposed inside the end of the reciprocating rod. This slot is optimally inclined only for centering saw blades of a single predetermined thickness. Since many saw blades exist with different thicknesses for the most various intended uses, sabre saws must be capable of receiving if at all possible all types of saw blade, in other words saw blades of any thickness, for the sake of universal utility.
The centering slot for receiving the saw blade lugs is therefore so wide that even the thickest saw blade fits into it. As a result, saw blades of lesser thickness have a certain lateral play within the centering slot. Because of this play of the chucking end, the danger of torsional and fluttering motions of the saw blade exists for the saw blades of lesser thickness, which are vulnerable to bending and twisting.
U.S. Pat. No. 3,750,283 discloses a sabre saw whose chucking device for the saw blades holds the lugs on its face end in V-shaped grooves and keeps the free end of the chucking end centered in a conical bore. As a result, regardless of its thickness, the saw blade finds a firm seat. The device for chucking saw blades functions securely and reliably. It circumferentially engages the reciprocating rod with a chucking tube and spring. However, this has the disadvantage that the lower diameter region of the end of the reciprocating rod opposite the upper end of the reciprocating rod is enlarged in steplike fashion. This is a visual obstacle for the user that hides the blade of the saw blade when the user is working with the sabre saw. Moreover, this saw blade chucking device is exposed to dust and metal chips, so that soiling can cause it to seize and make it harder to release the chucking device or change the saw blade.